In a Wideband Code Division Multiple Access (WCDMA) network, as well as in a Time-Division-Synchronous Code Division Multiple Access (TD-SCDMA) network, when UE performs multicarrier High Speed Downlink Packet Access (HSDPA) in a connected state, a network side notifies, through a reconfiguring message, the UE to perform an HSDPA downlink data service simultaneously on multiple carriers. The UE computes Channel Quality Indicators (CQI) corresponding respectively to the carriers according to channel quality of High Speed Physical Downlink Shared Channels (HS-PDSCH) received on the carriers, and reports the computed CQIs to the network side. The network side selects, according to the CQIs reported by the UE, HSDPA parameters such as a Transmission Block (TB) size, a number of HS-PDSCH code channels, a modulation mode, power, etc., corresponding respectively to the carriers. The network side then schedules the UE according to priorities of the UE corresponding respectively to the carriers based on the selected HSDPA parameters.
The UE computes the CQIs corresponding respectively to the carriers separately. The network side separately selects TB sizes, numbers of HS-PDSCH code channels, modulation modes, and power corresponding respectively to the carriers. Channels propagating wirelessly on the carriers attenuate relatively independent of each other. The UE has different priorities on the carriers. Accordingly, power of HS-PDSCH data allocated to different carriers differs a lot. In an extreme case, in a sub-frame, all HS-PDSCH data in fifteen code channels on one carrier may be scheduled for the UE, while no HS-PDSCH data on another carrier is scheduled for the UE.
When the UE performs multicarrier HSDPA in the connected state, it is disadvantageous to have HS-PDSCH power values, allocated to different carriers, that differ a lot. In a first aspect, when HS-PDSCH power values allocated to different carriers differ a lot, Adjacent Channel Selectivity (ACS) among multiple working carriers is low, leading to blockage of, and interference to, a signal on a low-power carrier, reducing channel quality. In a second aspect, when a terminal separates a digital signal on a carrier, HS-PDSCH power values allocated to different carriers with big differences may impact performance of an Automatic Gain Control (AGC) loop algorithm, such that a baseband signal fails to stabilize within a proper range before entering an Analog-Digital Converter (ADC), leading to signal saturation on a high-power carrier and insufficient signal resolution on a low-power carrier. Due to impact of the first and the second aspects, the channel quality of the signal on a low-power carrier may keep worsening, which signal may even not be able to be resolved correctly after multiple Hybrid Automatic Repeat Request (HARQ) retransmissions, impacting Slide Window Processing (SWP) over a data packet at a Radio Link Control (RLC) layer and a Medium Access Control (MAC) layer in a protocol stack, causing HSDPA downlink data accumulation, reducing a downlink HSDPA rate, thereby worsening downlink receiving performance of an HSDPA network.
To reduce a difference between power values of HS-PDSCH data of a UE on two carriers, a priority of the UE on a low-power carrier has to be increased. A formula for computing a priority in an HSDPA scheduling algorithm goes as follows.RelativePriotity=WeightofSPI*Rate*WeightofDelay/(1+HistoryFlux)  (1).
The WeightofSPI designates a fixed priority for scheduling a terminal configured by NodeB Application Part (NBAP) protocol signalling. The weightofDelay designates a delay weight for a Voice over Internet Protocol (VoIP) and a Circuit Switched (CS) Voice Service over High Speed Packet Access (HSPA), which is not a focus herein.Rate=w1(CQI_n)*TBSIZE(CQI_n)  (2).HistoryFlux(n)=HistoryFlux(n−1)*0.96+TBSIZE1+TBSIZE2  (3).
The TBSIZE1 and the TBSIZE2 are TB sizes respectively for scheduling a double-connection HSDPA user on a primary carrier and a secondary carrier.
It may be seen that in order to increase a priority of the UE on a carrier, a CQI corresponding to the carrier as reported by the UE has to be increased.